com.sun.xml.messaging.saaj.packaging.mime.util.LineInputStream Maven / Gradle / Ivy
Show all versions of saaj-impl Show documentation
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2012 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* http://glassfish.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
/*
* @(#)LineInputStream.java 1.7 03/01/07
*/
package com.sun.xml.messaging.saaj.packaging.mime.util;
import java.io.*;
/**
* This class is to support reading CRLF terminated lines that
* contain only US-ASCII characters from an input stream. Provides
* functionality that is similar to the deprecated
* DataInputStream.readLine(). Expected use is to read
* lines as String objects from a RFC822 stream.
*
* It is implemented as a FilterInputStream, so one can just wrap
* this class around any input stream and read bytes from this filter.
*
* @author John Mani
*/
public final class LineInputStream extends FilterInputStream {
private char[] lineBuffer = null; // reusable byte buffer
public LineInputStream(InputStream in) {
super(in);
}
/**
* Read a line containing only ASCII characters from the input
* stream. A line is terminated by a CR or NL or CR-NL sequence.
* A common error is a CR-CR-NL sequence, which will also terminate
* a line.
* The line terminator is not returned as part of the returned
* String. Returns null if no data is available.
*
* This class is similar to the deprecated
* DataInputStream.readLine()
*/
public String readLine() throws IOException {
InputStream in = this.in;
char[] buf = lineBuffer;
if (buf == null)
buf = lineBuffer = new char[128];
int c1;
int room = buf.length;
int offset = 0;
while ((c1 = in.read()) != -1) {
if (c1 == '\n') // Got NL, outa here.
break;
else if (c1 == '\r') {
// Got CR, is the next char NL ?
int c2 = in.read();
if (c2 == '\r') // discard extraneous CR
c2 = in.read();
if (c2 != '\n') {
// If not NL, push it back
if (!(in instanceof PushbackInputStream))
in = this.in = new PushbackInputStream(in);
((PushbackInputStream)in).unread(c2);
}
break; // outa here.
}
// Not CR, NL or CR-NL ...
// .. Insert the byte into our byte buffer
if (--room < 0) { // No room, need to grow.
buf = new char[offset + 128];
room = buf.length - offset - 1;
System.arraycopy(lineBuffer, 0, buf, 0, offset);
lineBuffer = buf;
}
buf[offset++] = (char)c1;
}
if ((c1 == -1) && (offset == 0))
return null;
return String.copyValueOf(buf, 0, offset);
}
}